Grundfos UPM3 Flex 25-70: PWM-ready, up to 7m head (video guide)

The Grundfos UPM3 Flex 25-70 is an A-rated circulator for underfloor heating and domestic heating. A heat pump or boiler can set its speed by PWM signal, and without a signal it runs at full speed on the curve you choose.

Watch the full video and the quick version below, and download the data sheet and install manual for the exact specification.

Key facts

• A-rated Grundfos circulator
• PWM speed control from the heat pump or boiler
• Full speed on your chosen curve without a signal
• 130mm port to port, 1 1/2" unions
• 5, 6 or 7m max head settings
• 2 to 52W
• Rated to 10 bar

How to fit it

1. Isolate the power and close the valves either side
2. Fit with new gaskets, arrow with the flow, motor shaft horizontal
3. Electrician connects the power, and the PWM cable if used
4. Fill, vent, choose the curve and run for 2 hours to clear air
5. LED 1 green with power on. A red LED means an alarm, isolate first

Buy it

The Grundfos UPM3 Flex 25-70 A-Rated Circulation Pump is available from MaxHeatUFH. Order by 12pm on a working day for next working day UK delivery. Trade customers see their trade price when logged in.

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